There are basically two procedures by which bricks are formed from clay into individual cut bricks and delivered to a setting head for emplacement on a kiln car. In the first method, at the pug mill a continuous slab of clay having cross-sectional dimensions equal to the length and width of a brick are continuously extruded therefrom. As the clay slab is extruded a rotating wire cuts the clay into individual bricks. The bricks then move down an off-bearing conveyor to the end thereof where they are assembled into rows of a desired number therein and pushed transversely onto a marshalling table. On the marshalling table the rows of bricks are stacked into double layers with the upper layer being inverted in an operation called "facing". The double layer rows are then assembled and delivered by some type of setter head onto a kiln car.
In the second procedure, clay slugs are extruded and cut to a prescribed length. The slugs proceed down a conveyor where they are stacked, one on top of the other, then pushed through a wire cutter onto a marshalling or spread table. As the slugs are passed through the wire cutter each slug is cut into a row of bricks and delivered onto a spread table. As a plurality of rows of brick accumulated on the spread table, a setter head will lift and transfer three or four double-layer rows onto a kiln car. One example of such a system is basically described in the Pearne et al U.S. Pat. No. 3,589,495.
In either system, regardless of the manner in which the bricks are cut, it is necessary to perform two operations. First of all, either the slugs or the cut rows of brick must be stacked into double-layer rows or groups of rows called "courses", as this is the manner in which they are transferred to the kiln car. Secondly, the upper layer of each row must be inverted in an operation called "facing" to protect the finished side of the bricks as they are fired.
In the aforementioned Pearne et al patent it is noted that the row slugs are stacked and faced, then pushed through a wire cutter to form the individual bricks. It has been found that pushing a double layer slug through a wire cutter will cause distortion in the edge of the bricks, as it is difficult to push that size and weight of clay successfully through the wire while making a clean cut. It would be preferable, as a result, to push only a single layer row of bricks through wire cutters then perform the stacking and facing operation afterwards. Therefore, there is a need for a system for stacking and facing cut rows of bricks subsequent to the cutting operation and prior to delivery to the setter head.
Secondly, where single rows are to be stacked and inverted simultaneously, single rows must be shuttled or conveyed to a position spaced from the succeeding rows on the push-off table to give the apparatus room to operate. To continuously stop successive rows at the same point to form double layer stacks is a difficult operation in conveying techniques.
Other examples of prior art which recognize the need for facing and the desirability of stacking double layer courses on kiln cars include: U.S. Pat. No. 1,413,402 to Hanley, Jr. which shows in FIG. 7 that courses may be inverted during the stacking thereof on kiln cars by a mechanism including a hoist and a detachable frame. In this patent an entire course is lifted, inverted and stacked together, rather than stacking and facing rows prior to the formation of entire courses (which include a plurality of rows).
In U.S. Pat. No. 2,955,717 to Segur et al rows of cut brick are formed and introduced to a grouping table on a pair of conveyors. A row of bricks is lifted from one incoming conveyor, inverted 180.degree. and set down on a second row of bricks which has been delivered by the other incoming conveyor. To lift a row of bricks from one conveyor, swing it through an arc of 180.degree. and deposit it on a second row of bricks which has been introduced from an entirely second conveyor involves the coordination and registration of several pieces of equipment which is very difficult, expensive and relatively unreliable. A close look at FIG. 15 of this patent will indicate the intricacy necessary to successfully perform this operation.
In U.S. Pat. No. 2,917,991 to Segur, bricks or rows of bricks are introduced on an inclined conveyor. An elevator lifts alternating rows, delivers them into a flip-over device 36, which flips over the elevated row and redeposits it on a preceedingly formed lower row.